Cellar Spider, Daddy Long-Legs Spider, Skull Spider
Pholcus phalangioides
Family Pholcidae (Cellar Spiders), Order Araneae. Key family characteristics include very long, delicate legs and an oval or elongated abdomen.
Physical Description
The spider has a small, pale, pear-shaped cephalothorax and an elongated cylindrical abdomen. Its proportions are extremely slender with exceptionally long legs relative to its tiny body.
Size Estimate
Body length is typically 7 to 10 millimeters, with a leg span reaching up to 5 to 7 centimeters.
Coloration & Markings
Pale gray, beige, or translucent yellowish-white coloration, sometimes featuring faint darker markings on the carapace and a patterned abdomen.
Web Type
Irregular, messy tangle webs built in corners of rooms, cellars, and dark crevices, lacking adhesive sticky silk.
Eye Arrangement
Eight eyes arranged in two triads on the sides of a raised median area, with a pair of smaller median eyes in front.
Leg Characteristics
Extremely long, thin, thread-like legs that lack heavy spination but possess high flexibility and a remarkable vibrating defense mechanism.
Venom & Safety Information
Venom Information
Contains neurotoxic venom that is highly potent to small insect prey but structurally ineffective and negligible toward human skin and physiology.
Medical Significance
Harmless to humans. Their chelicerae are generally too weak or too short to pierce human skin, and bites result in no significant medical symptoms.
Safety Recommendations
No safety measures needed as they are completely harmless. If relocation is desired, gently guide the spider into a cup using a piece of paper.
Habitat & Behavior
Habitat & Range
Cosmopolitan distribution worldwide; strongly associated with human habitations, basements, cellars, caves, and dark, humid structural corners.
Behavior & Temperament
Docile and non-aggressive toward humans. When disturbed, it rapidly vibrates its body in its web to blur its image against predators.
Diet & Prey
Insects and other spiders, including medically significant species like black widows, which they capture by throwing silk threads over them.
Seasonal Activity
Active indoors year-round due to climate-controlled environments, with increased wandering and mating activity observed during warmer months.
Description
The cellar spider is a familiar and harmless indoor companion, recognizable by its delicate, incredibly long legs and habit of hanging upside down in untidy webs in dark corners.
Key Features
Extremely long, fragile legs, elongated pale abdomen, irregular tangle web, and the signature rapid body-vibration defense behavior when disturbed.
Similar Species
Harvestmen (Order Opiliones), which are not true spiders and lack segmented bodies or silk glands, and spitting spiders (Scytodidae).
Life Cycle
Females carry eggs in a loose silk cluster held in their jaws. Spiderlings hatch and molt multiple times, reaching adulthood within a year.
Ecological Importance
Serves as an effective natural pest controller inside homes and buildings, helping to suppress populations of nuisance insects and other arachnids.
Conservation Status
Not evaluated by the IUCN, but populations are globally stable, widespread, and thriving commensally with human structures.
Interesting Facts
Despite an urban legend that they possess the most toxic venom of any spider, their fangs are incapable of effectively envenomating humans. They actively hunt and eat other spiders.
Photography Tips
Use macro lenses with adequate lighting to highlight the delicate leg structures and translucent body details. Photograph against a neutral wall background.
User Notes
Found this on the wall
Identified: 2026-10-02T01:30:27.837044